Lumbar Support and Method for Manufacturing a Lumbar Support

ABSTRACT

A lumbar support to be integrated in a seat frame is proposed, in particular in a seat frame for a motor vehicle seat, the lumbar support comprising a correspondingly bent guide wire ( 4 ) onto which a plurality of finger-like support elements ( 6 ) made from plastics and extending transversely to the lumbar support are injection moulded. Bracing wires ( 8, 10 ) for fastening a seat cover or seat upholstery, as well as a transverse wire ( 12 ) for the automatic actuation of a head restraint, can also be attached to the guide wire ( 4 ) by overmouldings ( 9, 11, 13 ). All plastics components can be made in a single step with the aid of a suitable injection mould.

The present invention relates to a lumbar support, in particular a lumbar support designed to hang in a seat frame or seat support and comprising a wire support, as well as a method for manufacturing such a lumbar support.

Lumbar supports are used in seat backs of any type to support the lumbar vertebrae- or lumbar region of people sitting on the corresponding seats. Moreover, lumbar supports are used in particular in motor vehicle seats and are substantially constructed from a wire support which appropriately stiffens seat upholstery but allows a certain flexibility to adapt to the posture and shape of the respective person. Such wire supports can, for example, comprise two longitudinal wires with a plurality of transverse wires extending widthways between the longitudinal wires, the transverse wires being wound at their end portions around the longitudinal wires and thereby being fastened to the longitudinal wires. The longitudinal wires generally have a larger diameter than the transverse wires, the wire support thus formed being able to be hung in a seat frame with the aid of springs or the like.

Moreover, relatively rigid lumbar supports are known in which a lumbar support basket generally made from plastics is used which can only be deformed to a certain extent, the curvature of the lumbar support basket, for example, being able to be adjusted for example by means of a bowden cable arrangement. In addition, a force transmission means to an automatic or active head restraint can be provided via a transverse wire, for example, so that in the event of a motor vehicle accident the head restraint is actuated by transmission of force via the transverse wire and is moved into an optimum position within a very short time. For this head restraint to be actuated correctly, the rigidity of the lumbar support must be relatively high, this being able to be achieved by wire reinforcements. The lumbar support can be attached rigidly to the seat frame, for example by a rivet connection with the aid of a plastics clip or the like.

The production process of such a relatively rigid lumbar support is described as follows. Firstly, the lumbar support basket and the clip for the rivet connection are injection moulded from plastics. A guide wire which forms a wire framework for the lumbar support and the transverse wire to actuate the active head restraint are bent and optionally provided with bracing wires which serve to fasten a cloth cover or upholstery on the rear side of the corresponding seat or with corresponding wire clips and fixed together by gripping. The aforesaid components are finally assembled to make the lumbar support arrangement and provided with a bowden cable- or control cable arrangement which allows the curvature of the lumbar support basket to be adjusted.

The aforementioned lumbar support and the corresponding manufacturing process are, however, associated with two fundamental problems. Firstly, the lumbar support requires a relatively high number of parts or components and, secondly, the assembly of the lumbar support is relatively costly.

A further lumbar support is known from WO 03/092440 A1, two longitudinal bars being connected by plastics transverse connections, injection moulded onto the longitudinal bars. The longitudinal bars are preferably made from metal and provided with hooks to hang the lumbar support in a seat frame. A separate lumbar support basket is constructed in one piece with individual transverse bars, the transverse bars and the lumbar support basket being able to be made in a single step from a plastics material with the aid of an injection mould.

This known lumbar support, however, requires two longitudinal bars in total, a plurality of transverse connections made from plastics and the lumbar support basket also made from plastics, so that the number of components is still relatively high and the manufacture relatively costly. Additionally, a relatively large amount of plastics material is required to manufacture this lumbar support which increases the manufacturing costs.

The object of the present invention is therefore to provide a lumbar support, in particular a lumbar support comprising a relatively rigid support surface or support base, which can be easily and cheaply manufactured. Furthermore, the object of the invention is to propose a suitable manufacturing method for such a lumbar support.

This object is achieved according to the invention by a lumbar support with the features of claim 1 and a method for manufacturing such a lumbar support with the features of claim 20. The sub-claims respectively define preferred and advantageous embodiments of the present invention. The lumbar support according to the invention comprises two longitudinal wire portions and a plurality of support elements made from plastics which are injection moulded onto the two longitudinal wire portions and extend transversely to the lumbar support between the two longitudinal wire portions and protrude laterally in a finger-like manner beyond the two longitudinal wire portions in the transverse direction. These support elements which are constructed in the form of lumbar support fingers—optionally together with the seat upholstery—give support to the back of a user in the seat and, by their position which is predetermined by the longitudinal wire portions, define the curvature of the lumbar support and thus the support of the spine. Furthermore, part of the force to actuate an optionally provided automatic or active head restraint is applied to the system via the support elements.

The two longitudinal wire portions can be constructed by a single correspondingly curved guide wire, the bending of the guide wire in the lower region of the lumbar support being in particular such that in the wire framework or wire support a certain resilience, and therefore elasticity, is incorporated in the guide wire. Suitable fastening means can also be provided on the guide wire, for example in the form of a fastening clip which can also be made from plastics, to fasten the guide wire or the lumbar support to a seat frame.

One or more bracing wires which, like the support elements, extend transversely or widthways from the lumbar support, can be injection moulded onto the longitudinal wire portions and onto the guide wire, in order that the cloth cover or upholstery can be appropriately fastened thereto, using a profile, on the rear side of the seat during seat manufacture. In particular, the size of the bracing wires can be such that they protrude transversely beyond the finger-like support elements. To fasten the bracing wires onto the longitudinal wire portions and onto the guide wire, overmouldings in the form of pins can be provided, which protrude from the longitudinal wire portions toward the rear and hold the bracing wires. Connecting means, for example in the form of clips, can be provided on individual support elements and constructed for heated seat plugs, these clips in particular being made from plastics in one piece with the corresponding support elements. A seat manufacturer can then put heated seat plugs onto these clips, which in turn are to be connected to a heated seat module.

Preferably, in the upper region of the lumbar support a transverse wire can be overmoulded with the guide wire, which is to be coupled to an active headrest system, and in the event of a motor vehicle accident serves to transmit force to the active headrest system and to actuate the active headrest function, in order therefore to adjust the corresponding head restraint within the shortest time into an optimum position for the respective user. In this connection the transverse wire is preferably fastened to the guide wire with the aid of a thicker overmoulding, this overmoulding being able to extend transversely to the lumbar support between the two longitudinal wire portions of the guide wire.

The finger-like support elements can be provided with embossed portions in order to prevent slippage on the guide wire. Moreover, to a certain extent the support elements can be bent outwards and curved from the plane formed by the guide wire and the longitudinal wire portions, in particular a convex portion from the aforementioned plane being formed in the individual support elements between the two longitudinal wire portions.

In principle, the lumbar support according to the invention therefore merely requires a guide wire as a wire component, a transverse wire and bracing wires moreover being able to be provided. The remaining components of the lumbar support are preferably all made from plastics, this applying particularly to the finger-like support elements, the connections between the transverse wire and the bracing wires and the guide wire, as well as the clips for the heated seat plug and the fastening clip. All plastics parts can be injection moulded onto the guide wire in a single step, in the embodiment with clips for heated seat plugs, a cable receiver, for example in the form of a clip-in device or the like, also being able to be constructed in one piece on the corresponding support element.

All in all, the lumbar support according to the invention can be simply and cheaply manufactured. For manufacture, the guide wire merely has to be bent into the desired form, all plastics components subsequently being able to be injection moulded onto the guide wire with the aid of a corresponding injection mould, in a single step.

The present invention can preferably be used on lumbar supports for motor vehicle seats, the invention however not being restricted to this preferred field of application, but able to be used generally in seats of any type.

The present invention will be described in more detail hereinafter with reference to the accompanying drawings with the help of preferred embodiments and in which:

FIG. 1 shows a rear view of a lumbar support according to a first embodiment of the invention,

FIG. 2 shows a front view of the lumbar support of FIG. 1,

FIG. 3 shows diagrammatically a possible fastening of the lumbar support shown in FIG. 1 and FIG. 2 in a seat frame,

FIG. 4 shows a rear view of a lumbar support according to a second embodiment of the invention, and

FIG. 5 shows diagrammatically a possible fastening of the lumbar support in a seat frame shown in FIG. 4.

A first embodiment of the present invention will be described hereinafter with reference to FIG. 1-FIG. 3.

The lumbar support comprises a wire support or wire framework, which is formed by a guide wire 4 bent in an appropriate manner. The guide wire 3 thus forms a first longitudinal wire portion 1 and a second longitudinal wire portion 2 which extend substantially parallel to one another longitudinally and vertically to the lumbar support. At the lower end of the lumbar support, the guide wire 4 is bent such that it extends from the first longitudinal wire portion 1 to the second longitudinal wire portion 2, at the same time integral resilience 3 being obtained in the guide wire 4, which gives the lumbar support a certain amount of flexibility and elasticity. In particular, the guide wire 4 on the lower end of the lumbar support is bent such that firstly the guide wire 4 extends outwardly from the first longitudinal wire portion 1, is subsequently bent over and then extends substantially parallel to the outwardly bent portion of the guide wire 4 to the second longitudinal wire portion 2, where the guide wire 4 is bent and extends substantially symmetrically to the bent portions on the lower end of the first longitudinal wire portion 1. The connection which leads from the first longitudinal wire portion 1 to the second longitudinal wire portion 2, therefore extends substantially parallel to the bent portions emerging from the longitudinal guide portions 1 and 2 and in a plane therewith, such that this connection relative to the plane formed by the longitudinal wire portions 1 and 2, is displaced slightly toward the rear. Additionally, this connection comprises a fastening clip made from plastics and injection moulded onto the guide wire 4, to fasten the guide wire 4 and the lumbar support to a seat frame (not shown in FIG. 1 and FIG. 2).

In the example shown in FIG. 1 and FIG. 2 a total of six finger-like and transverse support elements 6 are provided which form a support surface for the back of a person sitting on the respective seat, the support elements 6 being fastened by overmouldings to the longitudinal wire portions 1, 2 and being made from plastics. Moreover, the support elements 6 comprise embossed portions 7 which prevent the respective support element 6 from slipping on the longitudinal wire portions 1, 2 and on the guide wire 4.

As can be seen in FIG. 1 and FIG. 2, the support elements 6 are slightly bent or curved, in particular a convex or curved portion being able to be constructed toward the rear in the region between the longitudinal wire portions 1, 2.

In the embodiment shown in FIG. 1 and FIG. 2, a first bracing wire 8 is provided in the upper region of the lumbar support which also extends transversely to the lumbar support and serves to fasten a seat cover or seat upholstery. In the embodiment shown, the bracing wire 8 protrudes laterally beyond the finger-like support elements 6 and is attached to the two longitudinal wire portions 1, 2 with the aid of overmouldings 9 made from plastics, which in particular are constructed in one piece with the uppermost support element 6. Furthermore, in the lower region of the lumbar support a second bracing wire 10 is provided which is constructed similarly to the bracing wire 8 and is also fastened to the two longitudinal wire portions 1, 2 and to the guide wire 4. To this end, however, pins made from plastics are provided on the two longitudinal wire portions 1, 2 which are constructed in the form of overmouldings between the two lowest support elements 6 of the lumbar support and constructed therewith in one piece on the guide wire portions 1, 2 and protrude therefrom toward the rear, so that the bracing wire 10 displaced to the rear is held by the pins 10.

On the upper end of the lumbar support a transverse wire 12 is attached by an overmoulding 13 to the guide wire 4, the overmoulding 13 extending transversely between the two longitudinal wire portions 1, 2. The transverse wire 12 serves—when incorporated in a corresponding motor vehicle seat—to actuate an active or automatic head restraint, in the event of a motor vehicle accident, the force exerted by the user on the lumbar support being transmitted via the transverse wire 12 to the active headrest system to actuate the head restraint, whereby the head restraint is moved automatically into an optimum position to receive the head of the respective person.

In the lumbar support shown in FIG. 1 and FIG. 2, the curvature of the lumbar support results from the contour of the guide wire 4 and its longitudinal wire portions 1, 2, a suitable adjustment mechanism, for example in the form of a bowden cable or control cable, being able to be provided which acts on at least one longitudinal end portion of the lumbar support, in order to make appropriate adjustments to the curvature of the lumbar support.

Therefore, as wire components, the lumbar support comprises the guide wire 4 as well as the bracing wires 8, 10 and the transverse wire 12. Furthermore, as plastics parts, the lumbar support comprises the finger-like support elements 6, the overmouldings 9, 11 to connect the bracing wires 8, to the guide wire 4, the overmoulding 13 to connect the transverse wire 12 to the guide wire 4 and the fastening clip 5, all plastics parts being able to be injection moulded in a single step onto the guide wire 4 by means of a suitable injection mould.

FIG. 3 shows a possible integration of the lumbar support shown in FIG. 1 and FIG. 2 in a seat frame 14, the lumbar support being shown similarly to FIG. 2 in front view. It can be seen from FIG. 3 that the lower end of the lumbar support is attached to the seat frame 14 via the fastening clip 5, whilst the transverse wire 12 is coupled to a mechanism 15 to actuate an automatic or active head restraint.

FIG. 4 shows a rear view of a lumbar support according to a second embodiment of the present invention, the components corresponding to the components shown in FIGS. 1-3 being provided with the same reference numerals and only the differences to the embodiment shown in FIGS. 1-3 being described in more detail hereinafter.

No bracing wires are provided in the embodiment shown in FIG. 4. Moreover, the embodiment shown in FIG. 4 comprises clips 16 for heated seat plugs which are made from plastics and constructed in one piece with the two lower transverse finger-like support elements 6. The heated seat plugs to be attached to these clips 16 are connected to a corresponding heated seat module. The lowest support element 6 comprises means 17 for receiving the corresponding cable, which connects the heated seat plug to the heated seat module, this cable receiving means 17, in particular in the form of a recess in the lowest support element 6, being able to be constructed such that the cable can be guided by the support element 6 to the respective plug clip 16. The embodiment in the form of a clip-in device or the like is also possible.

FIG. 5 shows a possible integration of the lumbar support shown in FIG. 4 in a seat frame 14 of a seat, in particular a motor vehicle seat, reference being able to be made to the description of FIG. 3. 

1-24. (canceled)
 25. A lumbar support, comprising a first longitudinal wire portion and a second longitudinal wire portion, and a plurality of support elements made from plastics, which extend in a transverse direction of the lumbar support between the first and second longitudinal wire portions and protrude laterally in a finger-like manner beyond the first and second longitudinal wire portions in the transverse direction of the lumbar support, wherein the support elements are injection moulded onto the first and second longitudinal wire portions and thereby fixed to the first and second longitudinal wire portions.
 26. A lumbar support according to claim 25, wherein the first and second longitudinal wire portions are formed by a single correspondingly bent wire.
 27. A lumbar support according to claim 26, wherein a resilience is incorporated in the bent wire.
 28. A lumbar support according to claim 27, wherein the resilience is formed by at least one bent portion of the wire.
 29. A lumbar support according to claim 25, wherein the lumbar support comprises fastening means to fasten the lumbar support to a seat frame.
 30. A lumbar support according to claim 29, wherein the fastening means are injection moulded from plastics onto a lower portion of the bent wire.
 31. A lumbar support according to claim 25, wherein the lumbar support comprises at least one wire extending transversely to the lumbar support to fasten seat upholstery or a seat cover.
 32. A lumbar support according to claim 31, wherein the at least one wire is fastened to the first and second longitudinal wire portions by overmouldings made from plastics.
 33. A lumbar support according to claim 32, wherein the overmouldings protrude in a pin-like manner from the first and second longitudinal wire portions.
 34. A lumbar support according to claim 31, wherein at least two wires extending transversely to the lumbar support are provided to fasten seat upholstery or a seat cover, a first wire in an upper region of the lumbar support and a second wire in a lower region of the lumbar support being attached to the first and second longitudinal wire portions.
 35. A lumbar support according to claim 25, wherein at least one wire extending transversely to the lumbar support is attached to the first and second longitudinal wire portions for the automatic actuation of a head restraint.
 36. A lumbar support according to claim 35, wherein the at least one wire for the automatic actuation of the head restraint in an upper region of the lumbar support is attached to the first and second longitudinal wire portions by at least one overmoulding made from plastics.
 37. A lumbar support according to claim 36, wherein the at least one overmoulding extends transversely to the lumbar support from the first longitudinal wire portion to the second longitudinal wire portion.
 38. A lumbar support according to claim 35, wherein the at least one wire extends outwardly beyond the support elements transversely to the lumbar support for the automatic actuation of the head restraint.
 39. A lumbar support according to claim 25, wherein on at least one support element a connecting means is provided for a heated seat plug.
 40. A lumbar support according to claim 39, wherein the connecting means is made from plastics and is constructed in one piece with the corresponding support element.
 41. A lumbar support according to claim 25, wherein cable receiving means are constructed on at least one support element to receive a cable.
 42. A lumbar support according to claim 25, wherein the support elements are provided with embossed portions to prevent slippage on the first and second longitudinal wire portions.
 43. A seat according to claim 31 comprising: a seat frame; and a lumbar support installed in the seat frame.
 44. A method for manufacturing a lumbar support, comprising the steps of: providing a first longitudinal wire portion and a second longitudinal wire portion which extend substantially in a longitudinal direction of the lumbar support, and fixing a plurality of support elements made from plastics to the first and second longitudinal wire portions, such that the support elements extend in the transverse direction of the lumbar support between the first and second longitudinal wire portions and protrude laterally in a finger-like manner beyond the first and second longitudinal wire portions in the transverse direction of the lumbar support, wherein the plurality of support elements are fixed to the first and second longitudinal wire portions by injection moulding onto the first and second longitudinal wire portions.
 45. A method according to claim 44, wherein the first and second longitudinal wire portions are provided by a single wire being bent in order to construct the first and second longitudinal wire portions.
 46. A method according to claim 44, wherein at least one wire extending transversely to the lumbar support is attached by overmouldings made from plastics to the first and second longitudinal wire portions to fasten a seat cover or seat upholstery.
 47. A method according to claim 44, wherein at least one wire extending transversely to the lumbar support is attached by at least one overmoulding made from plastics to the first and second longitudinal wire portions for the automatic actuation of a head restraint. 